Effectiveness and Tolerability of Nonmedical Switching from Originator (MabThera®) to Biosimilar (Truxima®) Rituximab in People with Multiple Sclerosis: A Tertiary Single-Center Observational Study
Discuss this preprint
Start a discussion What are Sciety discussions?Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Background
Rituximab is used off-label for multiple sclerosis (MS), and biosimilar substitution raises a distinct extrapolation challenge, as MS is not an approved indication for the reference product. Real-world nonmedical-switching data inform biosimilar appropriateness decisions by clinicians, societies, and payers.
Objective
To report the effectiveness and tolerability of nonmedical switching from originator (MabThera®) to biosimilar rituximab (Truxima®) in people with MS (pwMS).
Methods
A retrospective, single-center observational cohort study of 50 pwMS switched after at least two originator infusions, followed for two years.
Results
Annualized relapse rate declined from 0.45 (95% CI 0.28–0.68) pre-rituximab to 0.02 (95% CI 0.00–0.13) on originator and 0.00 (95% CI 0.00–0.05) on biosimilar (p = 0.367 between products). In paired imaging analysis (n = 29), the proportion with active scans declined progressively (50.0%, 34.5%, 17.2%; Cochran’s Q, p = 0.040), with no difference between the originator and biosimilar periods (McNemar, p = 0.227). B-cell depletion deepened progressively. All patients remained on biosimilar through the end of follow-up.
Conclusion
Nonmedical switching from originator to biosimilar rituximab was associated with comparable clinical and radiological outcomes, supporting its use in pwMS without concern for inferior efficacy or diminished tolerability.
